Passenger transport vehicles, such as in particular buses and trains, coaches, apron buses and the like, are sufficiently well known per se. Usually, they afford more than four spaces, for the most part even more than eight spaces for passengers who may be brought to their destination by means of the passenger transport vehicle. The passenger transport vehicles are usually designed for a specific maximum number of passengers or a maximum permissible total weight.
For boarding and unboarding of passengers, such vehicles usually have doors, for example, electrically, pneumatically or hydraulically operated doors, which may often be operated fully automatically or semi-automatically. For example, the doors may be opened at the push of a button by passengers inside and outside the passenger transport vehicle. Depending on the purpose of use and the configuration of the specific vehicle, the doors may, for example, also be opened or closed at the push of a button by the bus driver, or it is possible for the passengers to push a signal transmitter, for example, pushbuttons arranged in the vehicle at multiple positions and/or outside on the doors, to lodge a request to open the door, which may then be put into effect by the vehicle automatically and/or by the driver after the vehicle has come to a standstill.
Optical systems for sensing occupants/passengers that may identify particular occupants/passengers via video monitoring and face recognition are also known, for example, from WO 2012/130808 A1.
On the other hand, there are also devices that, for example, using cameras and/or laser sensors, may detect the presence of occupants/passengers, regardless of their identity, and also the direction of movement of the occupants/passengers, in particular, in the entrance region of buildings. Such devices permit the presence of any occupants/passengers to be detected or else occupants/passengers to be counted and their direction of movement to be ascertained.